Sapman and nsp - thanks for your comments - I've just followed up with LP, and everything required has posted - they just need to put the bonus on now. I'm keeping my fingers crossed. Perhaps I will be the last one to get the bonus, but it doesn't really matter since I wasn't planning on using the miles in a rush. I still fundamentally believe that LP will survive, and that I will be able to use my miles.
And as most people I thoroughly enjoyed my trip - not my first one to South America, but certainly the most round-about one.